Studies are continuing on the biological properties of synthetic peptide analogs derived from the matrix protein, thrombospondin-1. We are collaborating with Drs. David D. Roberts and Henry C. Krutzsch (Laboratory of Pathology, NCI) in assisting in peptide analog design and in preparing and characterizing aggregated and polymer-conjugated forms as potential therapeutic agents. Thus far, we have focused on the inhibition of endothelial cell growth and tumor angiogenesis by stable peptide analogs from the second type 1 repeat sequence of thrombospondin-1. Further tests of the inhibition of human breast carcinoma in immunodeficient (nude) mice are currently underway. Patent applications have been filed.